Galvo Grid Error
Summarize radial positioning error from a galvo calibration grid.
Description
Galvo grid error combines paired x/y positioning deviations into radial error at each point.
Galvo grid error combines paired x/y positioning deviations into radial error at each point. Aggregate RMS includes any systematic offset.1
Summarize radial positioning error from a galvo calibration grid.
When to use Galvo Grid Error
Use this tool to summarize radial positioning error from a galvo calibration grid.
Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
How to use Galvo Grid Error and understand its results
- Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
- Enter xErrorsMillimeters, yErrorsMillimeters using the field table and calculation rules, then run the tool.
- Read rmsRadialErrorMillimeters, maximumRadialErrorMillimeters, sampleCount. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| xErrorsMillimeters | Grid X errors (mm) | list of number | Required |
| yErrorsMillimeters | Grid Y errors (mm) | list of number | Required |
Enter nonempty aligned finite signed mm error lists. Return radial RMS, maximum and sample count.
radial_i=hypot(x_i,y_i); RMS=sqrt(Σradial_i²/n) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| rmsRadialErrorMillimeters | RMS radial error (mm) | number; minimum: 0 |
| maximumRadialErrorMillimeters | Maximum radial error (mm) | number; minimum: 0 |
| sampleCount | Grid sample count | integer; minimum: 1 |
{
"input": {
"xErrorsMillimeters": [
3,
0
],
"yErrorsMillimeters": [
4,
0
]
},
"output": {
"rmsRadialErrorMillimeters": 3.5355339059327378,
"maximumRadialErrorMillimeters": 5,
"sampleCount": 2
}
}Limitations and assumptions
No correction surface, coordinate fit or measurement uncertainty is estimated.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use F-Theta Field Error: Compare measured scan position with the ideal f-theta field position. For a complementary task, use Rotary-Axis Calibration: Summarize rotary-axis calibration errors in arcseconds.
References
-
Galvo Grid Error — tool.io
Similar or alternative tools
- F-Theta Field Error
Compare measured scan position with the ideal f-theta field position.
- Rotary-Axis Calibration
Summarize rotary-axis calibration errors in arcseconds.